Recently, Device-to-Device (D2D) communication arises as a technique for communicating signals and data between terminals (devices) through a direct communication link without involvement of any network entity such as base station.
A D2D communication-capable terminal acquires synchronization with adjacent terminals and then discovers nearby terminals using a predetermined resource a predetermined time point. Next, the terminal acquires the device information on the discovered nearby terminals to start D2D communication. The device information may include identity information of the discovered device, interest, and application program information. When the D2D communication-capable terminal operates in connection with the base station, the terminal discovers the nearby terminal according to the configuration based on the time and resource information provided by the base station.
Meanwhile, Lawful Interception (LI) is the collecting of telecommunication data pursuant lawful authority for various reasons such as public interest and criminal arrest. Most countries have passed laws that require the telecommunications service providers to support the lawful inception of the law enforcement agencies. For lawful inception, the law enforcement agency collects data or voice signals distinguished between Content of Communication (CC) and Interception Related Information (IRI) associated with sessions initiated by a specific LI target.
In North America, Communications Assistance for Law Enforcement Act (CALEA) specifies LI. Recently, LI is performed even for the data communication service such as Voice over Internet Protocol (VoIP) as well as the voice communication service through cellular communication network.
In the Long Term Evolution (LTE) system, the data and voice are exchanged between User Equipment (UE) and Evolved Packet Core (EPC). Accordingly, the LI to a specific UE is performed in such a way that the Law Enforcement Monitoring Facility (LEMF) of the law enforcement agency receives information from an entity (e.g., P-GW) located at the termination of the LTE operator's network.
In the D2D communication in which the D2D UEs do not use the operator's network, allying the LI technology according to the related art without modification is difficult. In addition, there is a need of a technology capable of protecting against information distortion such as deformation and missing.
The above information is presented as background information only to assist with an understanding of the present disclosure. No determination has been made, and no assertion is made, as to whether any of the above might be applicable as prior art with regard to the present disclosure.